I'd like to offer perspective from 2 different, well... perspectives.
As a host: we offer a whole-house rental. We host quite a few extended family groups. Many of the people I get inquiries from in the X or Y generation are collecting information and it is the older people (parents, grandparents) who end up making the decision. Mind you, the last group we had was a multi-family and it was the "aunt" (mid-60's) who booked, but she also checked with the people in their 40's-50's about the final decision.
My son is 28 and he likes the experience of staying in peoples' shared homes or hostels when he travels so that he can more fully embrace the culture. I tend to look more for separated spaces. So the age of guest may play a factor in the type of Airbnb experience people are looking for.
As a guest: I plan travel all the time, from 2-person weekend getaways, to a group of 25 traveling to the other side of the world for 3 weeks. My current project is a 2.5 week motorcycle tour for 8 people aged 23, 28, 32, early-50's and early 70's. Everyone just always leaves it up to me to book - the "younger" ones don't have the patience to put it together and those in their 70's are technologically challenged.
So, I have to admit I don't think that limiting your questions to a particular age group (even if you've determined they have the most representation) will give you a rounded perspective. Just my 2 cents.